On NetTuts.com today there a new article with what they think is the best way to learn PHP in a list of thirteen different "assignments".

Learning something from scratch is almost always an arduous affair - you simply have no idea as to where to start, or not to start, to kick things off. I loathed learning about the idiosyncrasies of C++'s syntax when all I wanted to learn were some darn programming concepts. As I'm sure you can agree, this is a less than ideal situation. [...] Today, we're going to figure out the best way to learn PHP.

Among their list of "assignments" are things like:

Disregard the Naysayers

Read a Few, Good Books

Create Something Simple

Try out a Lean, Lightweight Framework

Build Something Awesome

Get Involved and Be Up to Date

There's also some good comments with suggestions of other frameworks to learn, things to try out and a few comments that put an emphasis on learning the language before diving directly into a framework.